 /*******************************************************************************
  * Copyright (c) 2000, 2005 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.texteditor;

 import java.util.ArrayList ;
 import java.util.HashMap ;
 import java.util.List ;
 import java.util.Map ;

 import org.eclipse.core.resources.IMarker;
 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IExtensionPoint;
 import org.eclipse.core.runtime.Platform;

 import org.eclipse.jface.resource.StringConverter;

 import org.eclipse.ui.editors.text.EditorsUI;


 /**
  * Provides the strategy for determining annotation types for given markers.
  *
  * @since 3.0
  */
 public final class AnnotationTypeLookup {

     /**
      * Record representing an annotation type mapping.
      */
     private static class AnnotationTypeMapping {

         final static int UNDEFINED= -1;

         String fAnnotationType;
         String fMarkerType;
         int fMarkerSeverity= UNDEFINED;

         boolean isMarkerSeverityDefined() {
             return fMarkerSeverity != UNDEFINED;
         }
     }

     /** The lookup table for marker to annotation type mappings. */
     private Map fMapping;

     /**
      * Creates a new annotation lookup object.
      */
     public AnnotationTypeLookup() {
     }

     /**
      * Computes the annotation type that corresponds to the state of
      * the given marker.
      *
      * @param marker the marker
      * @return the annotation type or <code>null</code>
      */
     public String getAnnotationType(IMarker marker) {
         String markerType= MarkerUtilities.getMarkerType(marker);
         if (markerType != null) {
             int severity= MarkerUtilities.getSeverity(marker);
             return getAnnotationType(markerType, severity);
         }
         return null;
     }

     /**
      * Computes the annotation type that corresponds to the given marker type and
      * the given marker severity.
      *
      * @param markerType the marker type
      * @param markerSeverity the marker severity
      * @return the annotation type or <code>null</code>
      */
     public String getAnnotationType(String markerType, int markerSeverity) {
         String annotationType= lookupAnnotationType(markerType, markerSeverity);
         if (annotationType != null)
             return annotationType;
         String [] superTypes= MarkerUtilities.getSuperTypes(markerType);
         for (int i= 0; i < superTypes.length; i++) {
             annotationType= lookupAnnotationType(superTypes[i], markerSeverity);
             if (annotationType != null)
                 return annotationType;
         }
         return null;
     }

     /**
      * Returns the annotation type for the given marker type and the given
      * marker severity.
      *
      * @param markerType the marker type
      * @param severity the marker severity
      * @return the annotation type
      */
     private String lookupAnnotationType(String markerType, int severity) {
         if (fMapping == null)
             initializeMapping();

         Object value= fMapping.get(markerType);

         if (value instanceof String )
             return (String ) value;

         if (value instanceof Map ) {
             Map severityMap= (Map ) value;
             return (String ) severityMap.get(new Integer (severity));
         }

         return null;
     }

     /**
      * Initializes the mapping between markers and their property values and
      * annotation types.
      */
     private void initializeMapping() {
         fMapping= new HashMap ();
         List mappings= getAnnotationTypeMappings();
         for (int i= 0, l= mappings.size(); i < l; i++) {
             AnnotationTypeMapping atm= (AnnotationTypeMapping) mappings.get(i);
             if (atm.isMarkerSeverityDefined()) {
                 Object severityMap= fMapping.get(atm.fMarkerType);
                 if (!(severityMap instanceof Map )) {
                     severityMap= new HashMap ();
                     fMapping.put(atm.fMarkerType, severityMap);
                 }
                 Map map= (Map ) severityMap;
                 map.put(new Integer (atm.fMarkerSeverity), atm.fAnnotationType);
             } else {
                 fMapping.put(atm.fMarkerType, atm.fAnnotationType);
             }
         }
     }

     /**
      * Returns the list of annotation type mappings generated from the
      * extensions provided for the annotation type extension point.
      *
      * @return a list of annotation type mappings
      */
     private List getAnnotationTypeMappings() {
         List annotationTypeMappings= new ArrayList ();
         // read compatibility mode
 readExtensionPoint(annotationTypeMappings, "markerAnnotationSpecification", "annotationType"); //$NON-NLS-1$ //$NON-NLS-2$
 // read new extension point
 readExtensionPoint(annotationTypeMappings, "annotationTypes", "name"); //$NON-NLS-1$ //$NON-NLS-2$
 return annotationTypeMappings;
     }

     /**
      * Reads the extensions provided for the given extension point name. Uses
      * the given type attribute name to create annotation type mappings that
      * are appended to the given list.
      *
      * @param annotationTypeMappings the list to be populated
      * @param extensionPointName the name of the extension point to read
      * @param typeAttributeName the name of attribute specifying the annotation
      * type
      */
     private void readExtensionPoint(List annotationTypeMappings, String extensionPointName, String typeAttributeName) {
         IExtensionPoint extensionPoint= Platform.getExtensionRegistry().getExtensionPoint(EditorsUI.PLUGIN_ID, extensionPointName);
         if (extensionPoint != null) {
             IConfigurationElement[] elements= extensionPoint.getConfigurationElements();
             for (int i= 0; i < elements.length; i++) {
                 AnnotationTypeMapping mapping= createMapping(elements[i], typeAttributeName);
                 if (mapping != null)
                     annotationTypeMappings.add(mapping);
             }
         }
     }

     /**
      * Creates an annotation type mapping from the given configuration element.
      *
      * @param element the configuration element
      * @param typeAttributeName the name of the attribute specifying the
      * annotation type
      * @return the annotation type mapping or <code>null</code>
      */
     private AnnotationTypeMapping createMapping(IConfigurationElement element, String typeAttributeName) {

         AnnotationTypeMapping mapping= new AnnotationTypeMapping();

         String s= element.getAttribute(typeAttributeName);
         if (s == null || s.trim().length() == 0) return null;
         mapping.fAnnotationType= s;

         s= element.getAttribute("markerType"); //$NON-NLS-1$
 if (s == null || s.trim().length() == 0) return null;
         mapping.fMarkerType= s;

         s= element.getAttribute("markerSeverity"); //$NON-NLS-1$
 if (s != null && s.trim().length() > 0)
             mapping.fMarkerSeverity= StringConverter.asInt(s, AnnotationTypeMapping.UNDEFINED);

         return mapping;
     }
 }

